Cover title.; "Research"--Cover.; "June 25, 2004."; Includes bibliographical references (pages 201-206).; Final report;; Performed by North Carolina State University Dept. of Civil Engineering for North Carolina Department of Transportation...

"July 2006."; Includes bibliographical references (p. 56-57).; Final report;; Performed by the Department of Statistics, North Carolina State University and Moorman, Kizer & Reitzel Inc., and sponsored by North Carolina Department of...

"April 3, 2007."; "FHWA/NC/2006-35."; "HWY-2005-22."; Includes bibliographical references.; Final report;; Performed by University of North Carolina at Charlotte, Civil Engineering Dept., sponsored by North Carolina Dept. of Transportation Research...